In an imaging environment, such as an imaging or a photograph editing application (e.g., Adobe® Photoshop®), pixel colors or color adjustments are frequently determined using undefined pixels where some information associated with those pixels is not initially known. For instance, in some cases, certain images are incomplete and result in portions of the image that are unclear, missing, and/or otherwise lack information. By way of example, images received over a network or captured via a camera may degrade and lack information for all pixels of the image resulting in unclear, blurry and/or other incomplete images. These images include a number of undefined pixels where information for those respective pixels is not known and a number of defined pixels where information for those respective pixels is known.
In other cases, compositing images or pasting an image over a background can utilize initially undefined pixels that lack color difference information to blend or transition the pixel colors. By way of example, a user may desire to paste an image, or portion thereof (e.g., foreground image) over a background image. In such a case, color modifications may be made in association with pixels, such as foreground pixels, in an effort to blend the images. The color modifications can be determined using a number of undefined pixels where color difference information for those respective pixels is not known and a number of defined pixels where color difference information for those respective pixels is known.
In some instances, a system of linear equations may be used to mathematically derive the unknown information of the undefined pixels. The mathematically derived information may then be filled into the undefined pixels to complete the degraded image. Deriving and solving the system of linear equations can require significant computing resources and can require an excessive amount of time to solve for the undefined pixels.
Further, in conventional implementations used to derive color modification information for initially undefined pixels, the transition in color of pixels across a boundary between a foreground image pasted in association with a background image can be visually recognized, that is, the seam can be observed between the images. For example, the pixel modifications made from the border of the foreground image inward may change too quickly thereby inhibiting a smooth transition. Such an apparent transition between images is oftentimes an undesirable result as a seamless transition between the pasted region and the background image is desired by a user so that the resulting image appears unaltered.